Association of FOXO3a with HSP70-1 and HSP90AA1 Expression in Bovine Mammary Epithelial Cells

Abstract

This study aimed to investigate whether the FOXO3a gene responds to heat stress and whether its expression is associated with the regulation of HSP70 and HSP90 in bovine mammary epithelial cells. Primary bovine mammary epithelial cells were isolated and cultured in vitro from bovine mammary tissue samples. Following the 11th passage, the cells were subjected to heat stress by incubation at 42 °C for 1 h in a water bath, followed by recovery at 37 °C. The kinetics of HSP70-1, HSP90AA1, and FOXO3a gene expression were evaluated at 2, 4, and 8 h after heat stress and compared with those of non-stressed cells. The results showed that HSP70-1 mRNA expression increased progressively and reaching peak levels at 4 and 8 h post-stress. Similarly, HSP90AA1 expression increased significantly from 2 to 8 h of recovery following heat exposure. FOXO3a expression increased following heat exposure and reached a highly significant peak at 4 h of recovery. These findings suggest that FOXO3a is responsive to thermal stress and may be involved in the molecular mechanisms regulating heat shock protein expression and cellular protection.